EVALUATION OF THE DETECTION OF BORRELIA-BURGDORFERI DNA IN URINE SAMPLES BY POLYMERASE CHAIN-REACTION

It is difficult in some cases to identify an infection caused by Borre lia burgdorferi and to monitor the effect of therapy. Seropositivity w ill persist even after successful treatment and therefore may suggest ongoing infection, For direct detection of B, burgdorferi DNA in human urine samples, the polymerase chain reaction (PCR) was evaluated, A p ublished primer system was selected, which amplifies a 259 bp fragment from the gene encoding the 23S rRNA. The lower detection limit of the primer system was 10 fg of extracted B, burgdorferi DNA, Several meth ods for the pretreatment of urine samples were tested, Of these, the G eneclean(R) kit (Bio 101, USA) showed the best results; A total of 114 urine samples from 74 patients belonging to three clinical groups was investigated: (i) 51 samples from 26 patients with active Lyme diseas e, (ii) 36 samples from 27 patients with previous infection but no sym ptoms at the time the urine was collected, and (iii) 27 samples from 2 1 seronegative control patients without Lyme disease, B, burgdorferi D NA was detected in 25 urine samples of 17 patients with active disease , whereas 26 samples from this group of patients were negative, Only o ne asymptomatic case with previous infection showed a positive result, and the urine samples of the patients without Lyme disease were unifo rmly negative, Two of four patients from whom samples before and direc tly after onset of therapy were available converted from negative to p ositive PCR results after initiation of therapy, accompanied by the sy mptoms of a Jarisch-Herxheimer reaction, It can be concluded from thes e results that a positive PCR from urine is,vith high probability an i ndicator of active Lyme disease, On the other hand, as only 17 of the 26 patients with active infection were positive, a negative PCR result does not exclude active infection.